If our ‘corrections’ system was actually geared as a deterrent, there would be daily hard labor for violent felons, absolutely no access to weights or any type of body building equipment, absolutely no opportunities to fraternize with other criminals, and no opportunity for radical groups posing as religious counselors to indoctrinate.
And a very low-protein diet, so they could not put on muscle mass.
I would like to see work encouraged. Be on a farm, learn a trade, etc. If you choose to work, you get better food. If you choose not to work, you stay in your cell and get bread and water.